May rhythms

The rhythms of the natural year let you know where you are, without the need to study the calendar. The first cuckoo or house martin tells us the warm weather of spring has finally arrived. The cycle of the moon in other parts of the world heralds great spawning events, with the gamete releasing coral polyps or the massed arrival of horseshoe crabs on the Nantucket coastline, both triggered by the phases of the moon. (Do follow the link and read about the Horseshoe Crabs. When you are done, explore Backyard and Beyond a little further – an always interesting and though provoking blog regularly updated Matthew Wills in Brooklyn, NY).Slightly less dramatic but no less consistent is the rising of the May-fly in southern England. Each spring, for a few short days, the air around our village is filled with them, elevating and descending on invisible escalators, rising and falling, rising and falling, their long tail hairs flicking behind them. In some years, numbers are enormous. As I return from work the car seems to attract them as they yo-yo up and down on to car roof, windscreen and bonnet, their internal biological switch bringing them to leave the water all at the same time to dance and fly in search of a mate.The adults do not feed at all and live a very short time after breaking from their larval cases, their sole purpose to find a mate and produce the next generation. Once found, fertilisation is completed and the females return to lay their eggs in the river. Hatching into nymphs they spend two years developing before their short time as adults bring their personal life-cycle to a close, entwined with the cycles of others, be they as food for fish or bird or calendorial signpost for this human.